BOISE - A trucking company hired by a subsidiary of General Electric Co. to ship massive oil refinery equipment to the tar sands project in western Canada hopes to begin moving the oversized loads along highways in eastern Oregon and southern Idaho, officials in both states say.

The first of the so-called megaloads could begin making its way from the Port of Umatilla in Oregon this weekend before crossing the Snake River and into Idaho's southwestern corner next week. The load's final leg in Idaho is now proposed along U.S. Highway 93, up Lost Trail Pass, with an elevation of 7,014 feet, and into southwestern Montana.

Oregon highway officials have already issued a travel advisory for the shipment, while engineers in Idaho are analyzing the route and potential impacts to infrastructure and public safety.

"We're in the process of doing bridge analysis for the shipment," said Adam Rush, spokesman for the Idaho Transportation Department. "We expect to have all of that wrapped up next week."

The new pathway has been proposed by Oregon-based Omega Morgan, the same company that moved one megaload shipment across U.S. Highway 12 earlier this year en route to the oil sands project in Alberta, Canada. But a second load was blocked by a federal judge who ruled in favor of the Nez Perce Tribe and environmentalists opposed to megaloads moving through tribal lands and a two-lane roadway that passes through a federally protected wild and scenic river corridor.

The load expected to begin its journey Sunday is 22 feet wide, 18 feet tall, 376 feet in length and weighs 901,000 pounds, dimensions that make it heavier and longer than the Omega Morgan shipment that chugged across northern Idaho and into Montana in August, Rush said.

Shaun Wiggins, spokesman for the GE subsidiary Resources Conservation Company International, declined to comment Thursday on the loads and new travel plan.

Like the first shipments, the freight proposed to move through Oregon and southern Idaho includes more components of a water purification system essential to the tar sands project.

This time, however, GE and Omega Morgan have mapped a route that will take more time in hopes of drawing little or no opposition.

Holly Zander, spokeswoman for Omega Morgan, said the shipment is scheduled to leave the Port of Umatilla Sunday night and head southeast through Grant, Baker and Malheur counties and the cities of Stanfield, Pendleton and Vale, mostly on U.S. and county highways, including the John Day Highway. The shipments are cleared to move only at night and pull over every 5 to 7 miles to accommodate traffic.

The load is expected to arrive in the small Idaho town of Homedale next week and begin the Idaho leg of its journey after the Thanksgiving holiday, Zander said. Idaho highway officials are studying a map that takes the load across the desert southwest of Boise before veering northeast to U.S. Highway 20 south of Bellevue, north on U.S. Highway 28 along the Lemhi River before merging on to U.S. Highway 93 through the town of Salmon before arriving in Montana.

Transportation officials in Montana say they have not yet received a complete application from Omega Morgan detailing a proposed route.

Two additional loads are expected to travel the same route next month, Zander said.